An unusual case of pneumonia.

A previously healthy 37-year-old man was admitted with a two-month history of increasing shortness of breath and high temperature. A chest X-ray demonstrated bibasal shadowing and small bilateral pleural effusions; arterial blood gases demonstrated low pO2. Despite intravenous antibiotics no significant improvement was observed. A high-resolution chest computed tomography showed diffuse ground-glass opacification with segmental and subsegmental airways opacification, indicating fine fibrosis. Subsequently, open lung biopsy showed diffuse alveolar damage and a histopathological diagnosis of acute interstitial pneumonia (Hamman-Rich syndrome) was made. Antibiotics were stopped and high intravenous doses of steroids were given with a dramatic improvement in the patient's breathing and radiographic findings. The pathophysiological mechanisms of acute interstitial pneumonia and current therapeutic options are discussed.